The reaction of H atoms with SnCl 4 was studied behind reflected shock waves at temperatures between 1020 and 1360 K and pressures around 150 KPa by applying atomic resonance absorption spectrometry for time-resolved measurements of H atoms at the L a line. The thermal decomposition of ethyl iodide (C 2 H 5 I) served as the H-atom source. For the reaction SnCl 4 + H ! SnCl 3 + HCl a temperature-independent rate coefficient of k 1 ¼ 3.5 AE 0.5 Â 10 13 cm 3 mol À1 s À1 was found for the temperature range of the present experiments.